Police could have reduced negative media coverage in the cases of Madeleine McCann's disappearance and Joanna Yeates's murder if they had given journalists off-the-record guidance, Daily Star crime correspondent Jerry Lawton told the Leveson Inquiry.

Lawton praised the way many UK forces share information with reporters, in particular West Yorkshire Police and Greater Manchester Police.

But he criticised Leicestershire Police, who assisted Portuguese detectives in investigating what happened to Madeleine, and Avon and Somerset Police, who led the Joanna Yeates investigation.

"Unusually both forces refused to give any guidance on any of the multiple lines of inquiry that came in to most newspapers during those on-going investigations," he said in a written statement.

Madeleine's parents Kate and Gerry McCann, and Christopher Jefferies, who was wrongly arrested over Joanna Yeates's murder, have told the Leveson Inquiry of their distress at a series of damaging newspaper articles about them.

Lawton noted in his statement: "It is surely of significance that the cases in which individual police forces have chosen not to engage with the press have resulted in some of the most vociferous complaints about coverage.

"Had Leicestershire Police chosen to give off-the-record guidance to the press about the state of the Madeleine McCann investigation then coverage may have been markedly different.

"Instead Leicestershire greeted every query with, 'It is a Portuguese police investigation, you need to contact the Portuguese police', in full knowledge - as you have previously heard in the inquiry - of the fact the Portuguese police refused to comment officially on any aspect of the case due to that country's official secrecy laws."

He added: "Had Avon and Somerset Police chosen to give discreet off-the-record guidance regarding Mr Jefferies' background and the nature of his arrest it is possible he may have been spared the ordeal he described to the inquiry.

Earlier in the day the inquiry heard claims from retired criminal investigator Dave Harrison that the News of the World potentially jeopardised the Suffolk Strangler investigation by spying on a surveillance team from the Serious Organised Crime Agency

Daily Express crime correspondent John Twomey, who is chairman of the Crime Reporters' Association, said it was "shocking" that the paper followed a police surveillance team.

"It's just quite unbelievable, really, that a newspaper should go to those lengths," he told the inquiry.

"I think it would have taken most reporters - certainly most crime reporters - by surprise."

Twomey denied a suggestion that journalists paid for meals in top restaurants with senior police officers as an "inducement".

He said former Metropolitan Police counter-terrorism chief Andy Hayman was "freer in the way he expressed himself" after having a glass or two of wine over lunch but never gave away any secrets.

The crime reporter also voiced concerns about a proposal that police officers should have to record all contacts with journalists.

He said: "If, say, a Detective Chief Inspector is anxious to get promotion in the future, and a rule like that is introduced, should it be, then he or she will probably cease all contact.

"Because when they go for promotion or maybe a selection board for a specialist CID unit, they don't want anyone to access the details and say 'Well, hang on, that person on the list three years ago, for instance, has seen crime reporters every now and again'."

Sunday Express associate editor James Murray, meanwhile, warned that The Guardian’s July 2011 revelation that NoW journalists listened to Milly Dowler’s voicemail messages could “fatally” damage relationships between journalists and the police.

He also told the inquiry he had heard stories in the past about the NoW employing former detectives or ex-special forces troops to carry out investigations.

He said he understood that the now-defunct Sunday tabloid used its resources to conduct surveillance to find out, for example, whether two celebrities were having an affair.

"There's a general appreciation that the News of the World - pretty much a lone wolf - was carrying out that sort of activity," he said.

The journalist also said that police officers could become less likely to divulge a good story after drinking alcohol.

"Some of the best information I've got is over a cup of tea when everyone is very sober," he said.